Since the vast underground space didn't originally exist without the Earth Spirit Worm, it must have been lured or attracted by something that was only found in this particular subterranean region.
Of course, the pure mana was the obvious conclusion.
However, it probably wasn't the only attraction the subterranean region offered the Earth Spirit Worm. After all, while the Earth Spirit Worm was a fourth-dimensional creature, it was still a being of earthen affinity.
The higher-quality earthly minerals in the pure mana-filled subterranean region would undoubtedly be more appealing than the moon's ordinary soil.
Vaan believed that was why there wasn't a single trace of metal in the underground space.
The Earth Spirit Worm must have consumed all the metal deposits within the area. The Divine-rank Stalactite Milk could have also been a byproduct of it.
